Sheetsx s sheet



p 1952 A. J. LAYBERGER 2,609,996

HAMMER MILL FEED DELIVERY CHUTE, INCLUDING DUST GUARD Filed Aug. 11, 1950 2 SHEETS-SHEET l U LVJ i LvJ w INVENTOR.

F|G 3 Arhur J. Lcyberger ATTORNEY A. J. LAYBERGER Sept. 9, 1952 HAMMER MILL FEED DELIVERY CHUTE, INCLUDING DUST GUARD 2 SHEETSSHEET 2 Filed Aug. 11, 1950 INVENTOR, 2 Arthur J. Luyberger ATTORNEY Patented Sept. 9, 1 952 HAMMERMILL FEED DELIVERY CHUTE, INCLUDING DUST GUARD Arthur J. Layberger, Havertown Pa assignor to Pennsylvania Crusher Company, Philadelphia, Pa., a corporation of New York' Application August 11, 1950, Serial No. 178,798

6C1aims. 1 I

I This invention relates to a dust guard for a reversible type hammermill to intercept the material carried up, aroundand toward the supply chute'by the hammers.

The object of this invention is to provide a hammermill crusher combining with the delivery chute a dust guard mechanism cooperating with the hammers and casing structure to intercept and divert this material and prevent it from being thrown upward toward the incoming supply.

Another object of this invention is to provide a dust guard that is inexpensive and durable in construction.

Other and further objects of this invention will appear from the following description taken in connection with the accompanying drawings of which v i Fig. 1 is a top view of the machine;

Fig. 2 is a cross-sectional view of the machine along lines 2-2 of Fig. 1;

Fig. 3 is a cross-sectional View along lines 3--3 of Fig. 1;

Fig. 4 is a fragmentary end view of another embodiment of the invention; and

Fig. 5 is a fragmentary side view of the other embodiment of the dust guard.

' Referring to Figs. 1, 2 and 3 of the drawings there is shown the hammers of a reversible type hammermill crusher mounted on a driven rotor (not shown) and subscribing a hammer circle H on rotation. A plurality of hammers are in each of the longitudinally extending rows as illustrated in Fig. 3. On each side of the rotating hammers are breaker surfaces I3 and I4 against which frangible material dropped through the delivery chute |2 are hit by the hammers and smashed against the breaker surfaces and shattered into smaller particles. Breaker surfaces are arranged on both sides of the delivery chute l2 and are spaced above the hammers I0 to form a breaker chamber I8. The breaker surfaces, are shown schematically since the detail construction and arrangement of these surfaces varies with the type of material to be crushed and the size of crushed material desired. These surfaces are preferably of the same construction on each side of the delivery chute so that the machine may be operated in either direction with the same resulting action of the material against the breaking surfaces. The broken material is carried by the hammers around and down to screen bars (not shown) where the broken material is further crushed and dropped through the screen bar. However dust formed by the crushing process tends to remain within the machine circle.

and be carried upwards and thrown with the air currents into the breaking chamber and up into the delivery chute interfering with the incoming material and eventually escapingout of the top of the delivery chute into the atmosphere.

To prevent the dust and air currents from entering the breaker chamber I8 and delivery chute l2 aplate 2| is positioned in the breaker chamber I8 between the end of the breaker surface |4 adjacent the chute l2 and the incoming material and extends almost down to the hammer circle I I as illustrated in Fig. 2. As the hammers I! approach the chute on a counterclockwise rotation the end of the plate or dust guard 2| breaks the momentum of the dust and deflects the dust and air currents back into the hammer The incoming material then drops substantially free from these disturbing currents and dust infront of the hammers l0.

When the rotor is turned clockwise the plate 2| is raised and the plate 20 is lowered into the breaker chamber preferable between the breaker surfaces l3 and the incoming material, and extending almost to the hammer circle I I. Thus a dust guard is provided for clockwise rotation to interrupt the returning dust and air currents and deflect them into the hammer circle.

The plates 20 and 2| are mounted within the delivery chute l2 and are suspended from rocker arms 24, 25 mounted on rotatable shafts 26, 21. The delivery chute is of a rectangular shape in cross-section extending the entire length of the crusher. The side walls are formed by the longitudinally supporting beams 40, 42 and side plates 3|, 33. The end walls are formed by the plates 30, 32 flared outwardly at their upper ends to form recesses 48, 49 for the rocker arms 24, 25. A rectangular shaped sleeve 28, shown in phantom by the dot and dash lines in Figs. 1 and 2, is positioned between the plates 20," 2| and the recesses 48, 49 and extends down to the end walls 30, 32 isolating the recesses 48 49 with the rocker arms 24, 25 from the incoming material.

The rocker arm 24 is journaled in and supported by the beam 4| and the member 5|. A drive gear 52 is mounted on the shaft outside of feed chute |2 to turn the shaft 26. A safety set collar 54 is mounted on the shaft tobear against the member 5| to hold the shaft 26 withthe gear 52 from excessive axial movement. The shaft :21 is similarly mounted in the end member 43 and the supporting member 56. A drive gear 51-! for turning the rocker arm 25 is mounted on the shaft outside of the feed chute. The safety set collar 58 andthe drive gear 51 holds the shaft 21 from excessive axial movement.

The drive gears 52, 51 are each respectively driven by the chains and sprockets 6B, 6 I, and 62, 63 mounted on the shaft 64 that is turned by the crank 65 and handle 66. The shaft M is journeled in supports 10, 1| rigidly fastened to the member 40.

The plate 2| is rectangular shape sheets of metal with side portions 15, 15 and is pivotally supported by pins 16, 11 rigidly secured to the exv tensions 14, 15 respectively and rotatably fitting into the slots 13, 19 of the arms 24, 25 respectively. The plate 2! slides along the longitudinal side wall of the delivery chute guided by the 1 projections BI, 82 secured below the flared portion to the end walls so, 32 respectively. As the rocker arms 24, 25 are turned by the crank 65; handle 66 and the plate 2| slides along the wall and the pins 13, 11 of the plate slide in the slots 18, 19 of the arms. The end of the plate 2! would then be above the breaker chamber and the rotor is free to revolve counterclockwise knockin the incoming material against the breaker plates l3.

Plate 2.6 of a rectangular shape with extensions 90,19l is similarly suspended from the other end of rock arms 24, 25. Pins 92, 93 are securely fastened to the opposite corners of the extensionsilil, 9! respectively and are pivotally mounted in the slotted opening 9 95 of the rocker arms 24, 25 respectively. As the rocker armis turned the plate 2?] slides up or down in the guides 96, 91 extending the lower edge into the breaker chamber almost down to the hammer circle. I

"This arrangement provides for a balanced structure around the shafts 28, 21 so that in shifting the plates only the frictional resistance and inertia of the parts need be overcome. However a single plate may be used as shown in Figs. 4 and 5.

In Figs. 4 and 5 another embodiment of the invention is shown instead of having plates on ach sideof the chute a single plate may be suspended from crank arms and swing from one side of the chute to the other on the reversal ofth'e rotation of the hammer. In Fig. 4 the suspension of one end of the plate is shown with the crank arm lili mounted on a shaft Hi2 and plate soc pivotally mounted at the outer end of the crank arm. A pin I05 supportingthe plate is fixedly mounted in the end of the platelllil and rotatably fits into a hole 1% in th crank arm so as the crank arm is shifted from one position to the other the plate we remains vertical. The plate I653 extends into the breaker chamber almost to the hammer circle forming a dust guard. The rotation of the crank arms is limited by the stops lilil, I84 upon metrically located on both sides of said feed chute and above said hammers to form a breaker chamber between said hammers and-said plates, a dust guard comprising rocker arms mounted on opposite walls of the delivery chute each rotatablymou nted at one end and at the other end r pivotally supporting a plate alon a longitudinal wall of the delivery chute positioned to extend into the breaker chamber between the delivery chute passage and breaker plates on the rotation of the rocker arms to form a deflecting barrier between the approaching hammers and the incoming material.

2. A dust guard for a hammermill having a delivery chute centrally spaced over a reversible rotor with hammers thereon and having breaker plates on both sides of the exit of said chute comprising two plates on oppositesides of said chute extendible toward said rotor up to and adjacent the periphery of the rotating hammers, rocker arms rotatably'mounted at a central point there- .of and pivotally and slidably supporting said plates at opposite ends of said rocker arms to alternately raise one plate while lowering the other plate to correspond to the direction of rotation of the hammers. I 3. A dust guard for interrupting the return of air and dust into the delivery chute of a reversible rotor with peripheral hammers and breaker plates spaced above said hammers comprisin a plate positioned along the inside of the chute and extendible up to the periphery of the rotating hammers, a crank arm at each end of said plate pivotally supporting said plate at the rotating end to readily shift the plate from one side of the delivery chute to the other side and extending into the space between the hammers and the periphery'of the rotating hammers.

4. A dust guard as claimed in claim 2 wherein the sides of the chute at the ends of the plates have recesses and the rocker arms are mounted in the recess clear of the material passing through the delivery chute. i

5. A dust guard as claimed in claim 4 wherein the plates have portions extending into the recesses.

6. In a hammermill having a delivery chute with end walls and longitudinal walls' cen trally positioned above a reversible rotor and feeding frangible material between the hammers on said rotor, said rotor crushing the frangible material against breaker plates cylindrically located on both sides of said feed chute and above said hammers to form a breaker chamber between said hammers and said plates, a dust guard for defleeting the returning dust and air currents withinthe periphery of the rotating hammers having a plate within said chute and extending along a longitudinal wall with a dust-deflecting lower portion positionable within said breaker chamber adjacent the breaker plates on one side of said chute and having the lower edge-of said plate adjacent the hammer circle to deflect the dust and air currents within the rotor, a crank armwithin said chute mounted on the end walls thereof and. pivotally connected to the upper end of said plate to remove the lower portion from adjacent said breaker plates to permit the crushing of the frangible material against said breaker plates on reversal of the rotor.

' ARTHUR J. LAYBERGER.

REFERENCES CiTED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,478,733 Wright Aug. 9, 1949 2, 14,111 7 Wilson July 4, 1950 

